Someone did this to a friend of mine. He left his phone at a table in our University commons while he went to go get food. Someone took the phone and sent out a bunch of texts to "txt for this ringtone" type places. He didn't notice anything different until the end of the month, where those companies all billed his cellphone provider for the paid services they rendered. Each one is about $4-7/month, so if you can send messages to multiple companies, you can jack a mark's phone bill up pretty quickly. When dealing with the companies and the cell phone provider, he also couldn't get the charges dropped, as the text coming from "him" was proof that he accepted the terms of their agreements. I think he was out $20 or $30 for the month, and since some of the companies didn't cancel the service immediately like they stated, he was stuck paying for some of them for 3-4 months.
I'm too lazy to find the numbers, but if you watch Comedy Central at night, they generally have the commercials fairly often, as do WB/UPN-type stations.
